This invention relates generally to commercial liquid containers and particularly to those molded of plastic material which are intended to be disposable and used for commercial distribution of liquids such as engine lubricating oil and the like.
Many liquid products such as cleansers, solvents and lubricating oils share a common method of manufacture, distribution and sale in that they are typically produced in bulk quantities and then packaged for sale to the consumer in small individual containers. The operation of filling the individual consumer containers with the bulk produced liquid is generally a fully automated operation in which the containers are sequentially passed through a filling station in which a group of downwardly projecting filler nozzles directs the liquid into the containers through upwardly facing container apertures.
One of the most common products so manufactured, marketed and distributed is engine lubricating oil which is processed in bulk quantities and usually packaged for sale in one quart containers. While the overwhelming majority of consumer containers for engine lubricating oil are of either one liter or one quart in volume, there has been a recent trend to also package and sell lubricating engine oil in four or five quart containers. In either event, the efficiency demands of the market place dictate that the container used be capable of easy and rapid filling and preferably be capable of multiple stacking in order to reduce shipping and storage costs. To date, these needs have for the most part been met with some success by the familiar one quart metal oil can which has a metal cylindrical container with flat top and bottom metal surfaces. To reduce weight and material costs, a hybrid container is widely used in which the top and bottom flat surfaces remain metal but the cylindrical side walls are made of a foil-coated pressed paper or cardboard material. Such containers are more subject to leakage than the all metal cans.
In either case, the packaging process essentially comprises initially combining the metal bottom metal portion and the side wall together and passing the can (minus its top) through the filling station of the process. Subsequently, the filled can is passed through a top assembly operation in which the metal top is attached by crimping or folding completing the sealing of the container. The familiar "oil can" container has persisted despite several disadvantages due primarily to the rapid filling made possible by the wide aperture offered by the can before its top is applied and the convenience of stacking offered by the flat, bottom and top surfaces of the oil cans.
Despite these two advantages, there remain, however, several disadvantages to the conventional oil can. For example, a special opener is required to remove the liquid from the can. Further, the construction is a three piece fabrication which results in a plurality of seams. This increases the possibility of leakage and greatly weakens the can's structure. The latter is particularly true in the case of the particle material side wall version of the can. In its most common use, that is, automotive engine lubricating oil, the small aperture through which engine oil is added to the crank case necessitates the use of a separate spout or funnel to avoid spilling.
These and other disadvantages of the commonly used oil can have spawned a great number of structures which include the use of a snap-on, reusable funnel which the consumer attaches to the upper side walls of the can once the can has been opened. Another structure uses a plastic bottle-like molded container in which the container top includes in a funnel shaped portion and an extending neck structure. In the latter case, a twist-off cap is also generally used to seal the neck.
While these structures provide some improvement in the consumer needs of easy access and resealability, the need for snap on funnels increases expense to the consumer and the molded containers with integral funnel and neck have the concomitant disadvantage of necessitating that fluid filling take place through the much smaller neck orifice of the container. This, of course, increases filling time and costs. Furthermore, such containers are usually impossible to stack for retail display and storage.
There remains therefore a need in the art for an inexpensive container which may be filled quickly, provides an integral pouring spout and is resealable and stackable.